Liquid biopsies using urine and plasma could be the future of lung cancer screening
University of Illinois College of Medicine researchers have developed an epigenetic-based approach that helps detect non-small cell lung cancer through liquid biopsies using urine and plasma.
In recent years, scientists have been using new techniques such as methylation-specific PCR — one of the most commonly used methods for epigenetic studies that assesses the changes in DNA expression without altering its sequence.
In a new paper published in the journal Clinical Cancer Research, Dr. Alicia Hulbert, assistant professor of surgery, suggests that liquid biopsy biomarkers based on methylation detection from plasma and urine could be used as an aid to computed topography (CT) screening to help guide the decision to proceed with further invasive procedures.
“Urine samples have the potential to be easily implemented in a primary care practice,” said Hulbert, lead author of the study who also is a member of the University of Illinois Cancer Center’s Translational Oncology Program. “Plasma and urine yield low false positive rates and the methylation of these genes is associated with a high risk of lung cancer independent of age, race or how much a person smokes.”
The strategy detects epigenetic changes in circulating DNA in blood and urine using a specific set of genes for lung cancer, the third most prevalent cancer in the United States. It is the primary cause of cancer-related death worldwide and its five-year survival rate is less than 20%. The majority of cases are diagnosed in later stages.
The National Lung Screening Trial, sponsored by the National Cancer Institute (NCI), was conducted to determine whether screening with low-dose helical computed tomography could reduce mortality from lung cancer. However, CT screening has a false discovery rate of nearly 96%.
“Biomarkers from liquid biopsy assays hold promise for enhancing the diagnostic accuracy of early stage lung cancer screening in conjunction with CT imaging,” Hulbert said. “In this regard, epigenetic molecular markers for early detection of lung cancer have been studied and developed for years.”
However, those methods had a significantly lower yield of detecting DNA in circulating liquid biopsies. Hulbert developed an improved DNA extraction method that allows for methylation detection from liquid biopsies with a process optimized and reduced to just six hours, along with the use of highly prevalent cancer specific methylation targets.
The study was funded by the University of Illinois Cancer Center, the National Cancer Institute’s Early Detection Research Network grant U01CA214165-03, and U.S. Department Of Defense grant 484 W81XWH-12-1-0323.
Written by Sam Hostettler